A Crazy ?

[Davers]

I've noticed in my area [mostly in the last 10 or 15 years ] that every time they build a Gas station or Walmart etc, that they build a retaining pond that is fenced off [usually with a higher overflow tower in the middle. I,m 99% sure it'e Code.

When these things are built is there some type of barrier put in the bottom to keep all the run off pollutants like oil , gas , & other auto liquids from slowly seeping into the ground?
Kinda like at a landfill.

Are these things good for the Ducks ,Geese & Frogs I see in them sometimes .

Just thinking. my wife says I think of some of the" stupidest stuff".

But like they say = Question Everything

Davers...............

 

[DDancer]

Most likely they are installing a lining in the retaining pond to keep the waters from seeping into the ground. Some area's don't require the liner... depends on codes for their construction. As to wild life I would not worry about it unless you intend to take something for dinner No mutant frogs or fowl I've ever heard of coming from such ponds but considering the run off they are catching~ let mother nature take care of it. Microbes work wonders in conjunction with plants and algae.

 

[SusanMN]

I think it is more to catch water run off than pollutants. Lots of times swampy areas are filled in for these stores or malls and water coming down has to go somewhere. Having their own holding areas stops it from overloading the runoff water lines.

 

[cw0909]

i wondered about it too, found this info
http://www.cherry-creek.org/Detention pond maintenance .pdf

 

[Msbeepbeep]

As long as you don't go digging in it for treasure....

 

[Boatlode]

Don't know about up there in Jawja, but down here before they can build something they have to first fill the lot. When they dig out dirt for fill, you end up with a pond. Most of the retention ponds here have bass in them, so obviously they are not polluted.

 

[luvsdux]

It's my understanding it is to catch runoff (water and pollutants) in order to keep it from adding pollutants to the natural water courses, acquafers and general environment.
luvsdux

 

[hvacker]

There is a legal requirement to retain water draining off your property. Parking lots shed a ton of water and the liability for damage to other properties falls on the source of the water.

 

[doggrowl]

Davers,

I work Construction and we just put in over a dozen of these "rain gardens" in the Washington D.C. area. They do have liners. The liner has to pass a perk test to ensure that the water will pass through and be absorbed by the soil instead of filling up and flowing over into the street and the stormwater system it is meant to divert rain water from in an environmental manner. The ponds on a construction site that has grading slopes are designed to keep water from washing into the adjoining area or into the waterways and the primary purpose of these is to allow sediment to settle out and the water has an overflow outlet near the top to let clear water flow. These do not always have a liner and are not usually required by the State/County Soil and Erosion Manual. The S&R Plan must be in place (these ponds, silt fence, sediment traps, etc) before construction activities commence. Fines for not having these in place start at about $10K - $25K...this is per violation per day. Sorry about the rambling answer, but thats it. HH

 

[Davers]

Thanks for the reply,s everyone.

Maybe not such a stupid question after all.

I really enjoyed doggrowl's reply thanks DG for the perfect answer .[ almost no detail is too much] imo

Davers